Coccidicide



Patented Apr. 20, 1943 coccmromn Graydon lS. McKee, Washington, WilbertMoody Wilson, Beaver, and Harry S. Johnson, Pittsburgh, Pa.

Applicationivray 15, 1939, serial No. 273,720

(ci. 16v-14) 6 Claims.

This invention relates to the destruction of the protozoan coccidium.

The coccidium is an earth-borne protozoan. which when present in theintestinal tract of fowls or mammals seriously injures, or kills, thehost. is practically impos-sible to free an Iinfected animal of them,since they are able to resist the attack of all those known agents whichthe animal is able to endure. It is, therefore, important to protectfowls and other animals against coccidia by eliminating the coccidiafrom areas which animals, and particularly young chickens, frequent. ICoccidia are very persistent in infected .areas as in poultry houses,poultry runs, barns, barnyards, paddocks, and the like, their presencehaving been detected for more than two years in disused areas from whichpotential hosts were absent. Ihis fact alone makes it diillcult toeliminate the coccidia, but a difficulty of greater importance indislnfecting areas infected by coccidia is the same fact which makes ita practical impossibility to free an animal of them once they havegained entrance into the animal as a host. This fact is that thecoccidium has a unicellular body including a soft innerportion'encapsulated by a thin but resistant tegument, or

' capsule, and because of `this capsule, coccidia vinfected areas, Thisdiscovery arose during re` search andexperiment conducted for thepurpose of discovering an eicient coccidicide from our underlyingdiscovery that artificially produced sodium nitrate is an effective`agent for that purpose. Our first discovery was that artificiallyproduced sodium nitrate is an eiective coccidicide,v and laterfound thatnaturally-occurring sodium nitrate has o'f itself no 'coccidicldaleffect. This we determined to be for the `reason that it has associatedwith it no sodium nitrite, whereas artificially produced sodium nitratecontains from 0.5% to 2.00% of sodium nitrite', and has Van averagecontent of about 1.62% of sodium nitrite.A

Sodium nitrite being thus the-active agent in Because of the nature ofthe coccidia it destroying the coccidium, we have had success in usingthe artic'ially prepared sodium nitrate for that purpose, and inexperimenting with sodium nitrite by itself, have found that `the sodiumnitrite acts much more rapidly in destroying coccidia vif it beassociated with sodium nitrate.

We, therefore, employ sodium nitrite, preferably in association withsodium nitrate, in freeing infected areas from the presence of coccidia.Our method of disinfaction is to apply sodium nitrite preferably inassociation with sodium -nitrate on the oor, walls, and equipment of abuilding', such as a chicken house, infected with coccidia, or on theground of chicken runs, barnyards, and the like, The material is appliedeither as a relatively strong solution, or in iinely divided form. Inthe latter variant of our method moisture from previous or subsequentsprin-y kling, or moisture naturally deposited from thc atmosphere, orgiven off by animals within a building, is depended upon to form asolution rendering the sodium nitrite effective. If young chicks are tobe introduced into a chicken house which is'known, or suspected, to beinfected with coccidia, our coccidicidal preparation (if used insolution) is desirably applied 12 to 24 hours before the chicks arebrought in. If the preparation is applied as a finely divided solid, asomewhat longer period for complete destruction. of the coccidia maydesirably be allowed.

Theaccompanying drawing, following closely as possible actualmicrophotographs, illustrate progressive stages in the destructiveaction of sodium nitrite upon a coccidium. In this drawing, Fig. I showsa coccidium in a high order -of magnification, before the organism issubjected to sodium nitrite. Fig. II illustrates the condition of thecoccidium immediately after contact of sodium nitrite with it. Fig. IIIshows thel next later stage in the progressive action of the sodiumnitrite. Fig. IV shows a stage in which the organism has been killed,and is in a noticeable state of disintegration. Fig.' V shows the finalstage of. disintegration to which the organism is brought bythe actionof the sodium nitrite.

More in detail to describe themechanism of destruction illustrated inthe drawing, in Fig. I

the coccidium will be seen to consist of a relatively sot unicellularbody l enclosed by a resistant tegument or capsule 2. Fig. II of thedrawing shows the capsule 2 penetrated`at 3 by the sodium nitrite. InFig. III there has been a marked breaking of the capsule at 4 and amarked destructive effect probably lethal has been caused to the innerbody. of the organism.

-. cidicidal preparation.

While we do not wish to commit ourselves to a theory of the action bywhich sodium nitrite deobserved, and as shown in the drawing, as con-While the above gives general directions as to o 'desirability inpreferred detailedfprocedure of the method of using the coccidicidalpreparation. it' 4 yis also illustrative of the fact that sodium nitritemay be used alone' as the sole consument of the sisting, first ofapenetration of sodium nitrite through the capsule 2 of the coccidium;and that the sodium nitrite, lwhen it has so penetrated, by reducinginternal pressure in the organism, causes i disintegration of theinterior body structure of the organism, and breakage of the capsule byatmospheric pressure. This would seem totev inture of the coccidium hasproceeded to a. readily noticeable extent, and in Fig. V of the drawingin which the disintegrated body l is shown. The theory is alsoconsistent with the apparent efiect of sodium nitrate in associationwith the actively destructive sodium nitrite.

It has been above observed that sodium nitrite of itself serveseventually to eliminate coccidia ibut that that action is slow, unlessit be associated with sodium nitrate. We have observed lthat sodiumnitrite of itself tends molecularly to agglomerate, to form a relativelynon-penetrating solution with water, particularly when present in lhighconcentration. If, however, sodium nitrate be included with the sodiumnitrite in a water solution, a proportionally less agglomerourcoccidicidal preparation.

.dicated particularly by Fig. IV of the drawing in which disintegrationof the interior' body stmoated, and more Ip'enel'frative, solution isformed for any concentration of sodium. nitrite. Apparently l the sodiumnitrate acts as-a vehicle for the sodium nitrite, facilitating themigration of the sodium nitrite through the capsule of the coocidil um.It is, therefore, desirable that the sodium nitrate be, for use undermost conditions, assomated with the sodium nitrite which is the activelethal agent. T

We have found that there is no critical limi-V tation as to theproportions in which sodium ni-v trate and sodium nitrite are includedin our colcgood results by using, as above noted, artificially preparedsodium nitrate which may contain as a relatively incidental constituentlas small a quantity as .5% of sodium nitrite. We have alsosatisfactorily used our coccidicidal preparation mixed to consist yof asmuch as 90% sodium nitrite to 10% sodium nitrate, and, as noted, wehave-elimi- Thus. We have obtained n nated coccidia lfrom infected areasby usingas a It may -be generally stated that if the cocci,

dicidal preparation is to be used by sprinkling it in a dry, finelydivided,l state, under conditions in which there will be bltsllghtmoisture available for dissolving the sodium nitrite, it isdesirable in such case to include the sodium nitrate in greaterproportion than if the preparation is to be used in solution, or in thepresence of an abundant supply of moisture, such as is had inrain-soaked ground, or immediately after washing out a chicken house, orother building. It is also desirable that if sodium nitrite greatlypreponderates in the preparation, that a solution of the Ipreparationshould not exceed a conlcentration of about in order to avoid retardingthe penetrating property of the sodium ni.- trite and unduly retardingits migration through the capsules of the coccidia.

preparation, and that it may be associated in any proportion withthe`lethally inert, but practically useful,o sodium nitrate. In vfurtherillustration, we may give the following results of experiments conductedby ils as illustrative of the actionof In these experiments there wasprepared a saturated suspension of. coccidia in distilled water. Varioussolutions of a coccidicidal .preparationin accordance with i ourinvention were brought into contact with the organisms on the slideofamicroscope and the results were microscopicallyobserved as follows:

Satmatcd suspension Treated with-sodi- No'action at all.

oi coccidia. umnitrato.

Do 1 drop andi dro `Killed but capsule 1% sodium, Y not ruptured. Ac-

trto. tlonllow. i Do l dro and l Internal structure` V 10%? sodium and:o l y ihm' d 1` hmlm '1in o ro an i. i ,op o e 30%) internal cture,trite. v 'capsulobrokem Do 1 dro and 1 drs? Internal structure 50%psodium e trite. i broken. Action A clowns `Do ldropnatfsolutvion .(Joll.structure oi eodiumnitrite changed and shell 83% added tofone 'Bully.,Aodropsat. is. tion much slower. D" 1 aihh i..u,"' d

lndldm L Nd. t5. f Do Smsalsnimmodhto- Action very rapii,

y1 vo capsule oxpan s. 10% sod. nitro i mdbnoks. psedinsteadofl%i Thesetest experimenta'in to illustrating the .fact that sodium nitriteisalethal agent `for coccidia, show that the nitrite is retarded if'solutions ofthesodimn niy i trite above a certain concentration be madewithout including sodium nitrate. The i test experiments also show thatit is not a .necessary feature of the coccidicidal action that thecapsules of the cdceidia be actually ruptured; but .that the organismmay be killedby a dilation cf its en-f circling capsule unaccompanied byan actual :urpture of the capsule, such asthe ruptiu'e shownin theaccompanying drawing. It appears ytoIbe a fact, however, that actual.rupture of the capsules is indicative of a rapid destruction' of thecoccidia.

the organisms is caused by, or accompanied by, a lowering of pressureinthe organism. It does not appear, however, whether such lowering ofpressure is a general eifect of the nitrite, or is from, orthroughinert, it is desirable that the preparation be packed and sealed inmoisture-'proofcontainers prior to its use, in order that gradualconversion o f sodium nitrite into sodium nitrate may not take place. Itis also desirable to associate with thechemicals of our preparation amoisture-absorbing substance which will be preferentially wet It appearsthat the dilation of the capsules of the coccidia which results 'indeath to' by water, such as rice iiour, or a siapilar absorbentsubstance.

In the laboratory the results obtained by using sodium nitrite closelyparallel the results obtained by the use of iodine. Whereas iodine is,however, an impractical substance for use under the conditions existingin actual disinfection against coccidia, sodium nitrite is from everyconsideration wholly practical under those conditions.

This is in lpart a continuation of our pending application Serial No.138,472, iil'ed April 22, 1937, which it is punposed to replace.

We claim as our invention:

1. A coccidicidal preparation containing sodium nitrite. i

2. A coccidicidal preparation containing sodium nitrite and sodiumnitrate.

3. A coccidicidal preparation containing sodium nitrite and sodiumnitrate with the sodium nitrate preponderating in the preparation.

4. A coccidicidal .preparation having sodium nitrite as its chief lethalingredient. l

5. The herein described method o1' disinfecting an area purposed foranimal occupation against infestation by the protozoan coccidium whichconsists in destroying the coccldia adjacent the surface of such area.by the lethal action of sodium nitrite introduced on the surfacethereof.4

6. The herein described method of dlsinfecting an area purposed foranimal occupation against infestation by the 'protozoan coccidium whichconsists in destroyingthe coccidla adjacent the surface of such area bythe lethal action of sodium nitrite introduced on the surface thereof inassociation with sodium nitrate.

GRAYDN s. Maxam; W. MoonY WnsoN. HARRY s. JoHNsoN.

